Not Applicable
Not Applicable
The present invention relates to a cartridge-based printer and associated cartridge, and more particularly to a method and apparatus for identifying a cartridge inserted in a cartridge-based printer.
There are a number of U.S. patents that disclose electronic apparatus for printing indicia on labels, some of these are restricted to hand held units and others that disclose tabletop units. Hand held labeling machines are disclosed, for example, in U.S. Pat. Nos. 4,264,396, Stewart; U.S. Pat. No. 4,407,692, Torbeck; U.S. Pat. No. 4,473,426, Goodwin et al.; U.S. Pat. No. 4,477,305, Hamisch; U.S. Pat. No. 4,490,206, Makely; U.S. Pat. No. 4,497,683, Hamisch; U.S. Pat. No. 4,498,947, Hamisch et al.; U.S. Pat. No. 4,511,422, Hamisch et al.; U.S. Pat. No. 4,544,434, Mistyurik; U.S. Pat. No. 4,556,442, Torbeck; U.S. Pat. No. 4,561,048, Hamisch et al.; and U.S. Pat. No. 4,680,078, Vanderpool et al. Tabletop units for this general purpose, some of which are portable are described in U.S. Pat. Nos. 4,440,248, Teraoka; U.S. Pat. No. 4,501,224, Shibayama; U.S. Pat. No. 4,630,538, Cushing; and U.S. Pat. No. 4,655,129, Wirth et al.
The electronic machines for printing labels of the type disclosed above all include the same general combination of elements, a print head, means for feeding labeling media to be printed past the print head, a microprocessor, a read only memory programmed with appropriate instructions to operate the microprocessor, a random access memory, a keyboard with letter, number, and function keys for the entry of alphanumeric information and instructions concerning the indicia to be printed, and a visual display such as a LED, LCD unit to assist the operator in using the machine. In a hand held printer, these components may all be enclosed in a single housing.
The labeling media comprises labeling material attached to a carrier strip, and is fed through the printer. Legends, or other indicia, are printed on the labels by the printer. The printed labels are then removed from the carrier strip and attached to the objects needing identification. As there are many types of label applications, there are many combinations of labels and carrier strips that provide labels of varying sizes, colors and formats.
A particular type of print head employs thermal transfer printing technology. Thermal transfer printing uses a heat generating print head to transfer a pigment, such as wax, carbon black, or the like, from a thermal transfer ribbon to a labeling media. By using digital technology, characters are formed by energizing a sequence of pixels on the print head which in turn melt the wax or other pigment on the ribbon transferring the image to the labeling media.
Many prior art thermal printers include various means and methods for automatically identifying a width or identifying a characteristic feature of a labeling media or tape associated with a cartridge inserted in a cartridge-based printer. For example, U.S. Pat. No. 5,492,420, Nunokawa, discloses a plurality of holes formed on the bottom of a cartridge wall wherein the depths of the holes are varied to selectively trip a plurality of switches in the cartridge holder, thereby providing an indication of the type of cartridge that has been inserted. Similarly, U.S. Pat. No. 5,553,818 discloses a portable printer in which a plurality of plunger assemblies in the printer mechanism are selectively activated depending on the configuration of a plurality of punch-out tabs in the cartridge to provide an indication of the type of cartridge inserted in a printer. Another similar system, U.S. Pat. No. 5,562,353 discloses a tape printing apparatus in which microswitches in the printer are selectively tripped by projections on the cartridge to provide identification information.
While a number of identification circuits for identifying a cartridge inserted in a cartridge-based label printer are therefore known in the art, these systems typically require complicated switching systems which require a number of moving parts, and are therefore relatively expensive to implement. Furthermore, due to the number of moving parts, repetitive insertion and removal of a cartridge from the printer can cause significant wear on the switching systems, which can lead to incorrect identifications, maintenance problems and even failure of the printer. A need exists, therefore, for a cartridge identification system for use in a hand held cartridge-based label printer which is inexpensive to construct, reliable, and easy to maintain.
The present invention provides a method and apparatus for identifying a cartridge inserted in a cartridge-based printer. Generally, a first plurality of electrical contacts are provided on the printer cartridge. As the printer cartridge is inserted into the printer, a second plurality of electrical contacts in the printer mate with the first plurality of contacts, providing an identification of the cartridge to internal printer circuitry. The identification provides information relating to characteristics of the inserted cartridge, and more particularly identifies a width of a labeling media contained in the cartridge
More specifically, the cartridge-based printer includes a plurality of spring contacts which extend axially into a cartridge receptacle. The spring contacts are each electrically coupled to a printed circuit board in the thermal printer device, where they are selectively connected to a circuit common and/or a reference potential. The cartridge includes a printed circuit board or other conductive media supplying a second plurality of electrical contacts. When the cartridge is inserted in the cartridge receptacle, the electrical contacts coupled to the wall of the cartridge selectively connect one or more of the spring contacts in the cartridge receptacle to another of the spring contacts in the cartridge receptacle, providing an electrical identification signal identifying the cartridge, and more particularly a width of the labeling media in the cartridge.
The spring contacts are designed to elastically deform and to provide a spring force opposing the cartridge when the cartridge is inserted into the cartridge receptacle, and to expand when the cartridge is removed. The force provided by the elasticity of the spring contact therefore provides and maintains a strong electrical connection between the conductive material coupled to the cartridge and the printed circuit board in the printer. Furthermore, due to the ability to expand and contract, the spring contacts can provide an accurate identification of the inserted cartridge, even when there are minor variations in the size of the cartridge or in the alignment of the cartridge in the cartridge receptacle.
The second plurality of electrical contacts are preferably constructed as a printed circuit board. The printed circuit board can be constructed of typical circuit board materials, or can comprise a flexible printed circuit board, a metallized tape, or other conductive material. The printed circuit board is preferably adhesively coupled to the wall of the cartridge, thereby providing an inexpensive means for identifying the cartridge.
A general objective of the present invention is to provide a method and apparatus for automatically identifying a characteristic of a cartridge inserted in a cartridge-based printer which is inexpensive to implement. This objective is accomplished by providing an identification circuit which comprises an electrical connection between inexpensive electrical spring contacts and a printed circuit board.
Another object of the invention is to provide a method and apparatus for automatically identifying a characteristic of a cartridge inserted in a cartridge-based printer which has high durability. This objective is achieved by providing an electrical identification circuit with a minimal number of moving parts.
The foregoing and other objectives and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims herein for interpreting the scope of the invention.